Author Topic: 21 inch cafe? (Read 62134 times)

eldar · « **Reply #125 on:** January 07, 2009, 03:41:49 PM »

I dont know. Aluminum is pretty tough and sheds heat well!

547 · « **Reply #126 on:** January 07, 2009, 04:04:47 PM »

Quote from: Industrial Cafe on January 07, 2009, 03:31:17 PM

you mean they'll demetamorphose into wood?
they're aluminum now... I don't want to go back a step in my "ball toughness" evolution.

I wish they were brass

maybe you could toughen them up with your sit up technique. that in itself is pretty ballsy.

greenjeans · « **Reply #127 on:** January 07, 2009, 04:09:03 PM »

They laughed at Christian Dotson when they saw what he wanted to do:

stir, stir, stir

Industrial Cafe · « **Reply #128 on:** January 07, 2009, 04:23:09 PM »

yeah... I LOVE THAT BIKE.

eldar · « **Reply #129 on:** January 07, 2009, 04:31:30 PM »

Now a 21 inch wheel does not seem so outlandish does it.

Industrial Cafe · « **Reply #130 on:** January 07, 2009, 04:53:50 PM »

oh man, speaking of outlandish... this bike is stupid. I bet when he sits on it, the last tire on the swingarm sticks up like a sissy bar.

talk about ignoring the fundamentals of "purpose built" motorcycles

cafe750 · « **Reply #131 on:** January 07, 2009, 05:45:51 PM »

Quote from: eldar, Master of the K8 Thunder! on January 07, 2009, 04:31:30 PM

Now a 21 inch wheel does not seem so outlandish does it.

You can glue whatever you want onto a custom frame...it's never outlandish on a one off piece...

HavocTurbo · « **Reply #132 on:** January 07, 2009, 05:53:29 PM »

Ok so I gave up on reading all that BS....

Back to the task at hand:

Did you find wheels or not?

My thought was to widen them to the largest possible size that fits in the stock swingarm width.

OR

Use a different swingarm with an offset front sprocket.

Industrial Cafe · « **Reply #133 on:** January 07, 2009, 06:59:36 PM »

yeah, I found out the harley 21x3.0- 40 hole, will fit a 120/70/21 for the back.
the tire I took off, before I put on a 16" rim, was a 110/90/18. so the width should be about 1cm. more with the lower aspect of 120/70. -about 5 inches wide inflated, when measured with a caliper. which is the "tall and skinny" look I'm going for.

I dont know if you read up about 2 pages or not, but right now I'm broke.

the front will be easy, I'll just throw the same wheel on it with the standard 21" spoke kit for the cb750. and use the same size tire I guess.

I think it'll be a blast.

754 · « **Reply #134 on:** January 07, 2009, 08:38:23 PM »

Correct me if this is wrong?

I am getting the impression that geeto is thinking that mounting the 21 will make the bike go downhill and have little wheel travel?..and screw up the handling.

My impression is that from the swingarm pivot forward need not change 9with possible exeption of lowering) and it can have good suspension travel, by doing some of the following, extended swingarm, change of seating position, notching the brace on the frame in the seat area, changing shock mounts, etc.. Any or all of that will get it done in my opinion.

Easy way to find out if it works, try it with the skinnier tire, and go bigger if he likes it.

___________________________________________

How is it that boardtrackers ran sustained spedes of 80 -100 mph with cotton cord real rubber tires (90 YEARS AGO

), and now someone is saying it could not be done with a modern tire??

Some H-D models come with 21 front, and can do wheelies, how much weight do you suppose is on THOSE tires ?

Industrial Cafe · « **Reply #135 on:** January 07, 2009, 08:56:38 PM »

Quote

754
Some H-D models come with 21 front, and can do wheelies, how much weight do you suppose is on THOSE tires ?

seven tons.

754 · « **Reply #136 on:** January 07, 2009, 09:07:46 PM »

I can tell you there is more weight on a front HD 21 than there will be as a rear on a Honda.

The very first 21 rear bike that I recall (& I have a pretty good memory on custom bikes) was...

Barry Cooney,s "Tale of 2 Cities" that he co-built with Alen Ness, back in the 70,s or early 80,s. Quite a nice looking chopper , guess what it used for a rear hub?

CB750..

At any rate it is not a new idea, but go for it.. i will give you some support..

Industrial Cafe · « **Reply #137 on:** January 07, 2009, 09:27:35 PM »

cool.

I'll look up that chopper, it sounds familiar.

billybobobrain · « **Reply #138 on:** January 07, 2009, 09:50:53 PM »

Quote from: Industrial Cafe on January 07, 2009, 04:53:50 PM

oh man, speaking of outlandish... this bike is stupid. I bet when he sits on it, the last tire on the swingarm sticks up like a sissy bar.

talk about ignoring the fundamentals of "purpose built" motorcycles

I wish I was cool like him!

XN · « **Reply #139 on:** January 07, 2009, 10:02:33 PM »

As for the 21" wheel debate not working well and supporting weight. My VTX rides just fine (120 series tire). With me on it I would say its around 1000 pounds.

There are plenty of custom Harleys out there that ride a 90 series 21 and I'm sure most of them weigh more than a CB...

Industrial Cafe · « **Reply #140 on:** January 07, 2009, 10:34:29 PM »

Thats what I'm sayin. Damn the torpedos!!

I like big wheels, loud pipes, and ho's.

old750 · « **Reply #141 on:** January 07, 2009, 10:41:48 PM »

Quote from: Geeto67 on January 07, 2009, 01:12:07 PM

I measure and use real motorcycle chassis principles. I tell you what I'll save the search function, I am building this and have been doing it off again and on again for 5 years (most of that has been reading lots of engineering journals, books, and other publications on motorcycle chassis design).it is the first h1 500 chassis to use the FZR400 swingarm conversion, it is the first to use the fzr600 front end (and I didn't see a lot of guys doing stem swaps on triple clamps before I started posting about it in 2002):

Hey Gheto67 very nice build lol did you engineer and custom fab that frame all by yourself?

Looks like you swapped out a front end and swingarm out of a nice bike and installed in on a rat bike

Just wondering if you have the titles of those journals and books I'd be interested in reading up on it. I've only found one book on motorcycle chassis design.

HavocTurbo · « **Reply #142 on:** January 07, 2009, 11:21:59 PM »

Alright I guess I'll play parent...

Will you all please just shut up if you aren't going to offer something constructive to the thread.

Sure he asked for opinions. And just like a-holes everyone's got them. We're past that now.

Even if he has lack of $$ it will still be nice to try to at least get a parts list going so that when there is an in flux of cash they will be bought.

Ind.Cafe please recap all the parts (in a list if you would) you are either looking at using or thinking of modifying.

Thank you.

754 · « **Reply #143 on:** January 07, 2009, 11:30:34 PM »

Trying to think when i did my first stem swap?

I remember doing one for mockup back in 87 or 88, but i don think it was anthing new then..pretty sure it was not new in the 70,s either...

____________________________________________________________

What I see on here is someone talking about some concept they want to try on their bike..

Some like the idea, some dont.

So why should the thread get yanked ? No reason I can see. Should some interpersonal stuff get edited??..perhaps.. but that is not the subject of the thread, and changing that would leave the main subject intact..

HavocTurbo · « **Reply #144 on:** January 07, 2009, 11:40:37 PM »

Quote from: 754 on January 07, 2009, 11:30:34 PM

Trying to think when i did my first stem swap?

I remember doing one for mockup back in 87 or 88, but i don think it was anthing new then..pretty sure it was not new in the 70,s either...

____________________________________________________________

What I see on here is someone talking about some concept they want to try on their bike..

Some like the idea, some dont.

So why should the thread get yanked ? No reason I can see. Should some interpersonal stuff get edited??..perhaps.. but that is not the subject of the thread, and changing that would leave the main subject intact..

I did my first step swap in 86.... was 4 years old. Helped my grandfather and everything. Honest. Indian front end on a harley.

Did my first "solo" stem swap in 98 during senior year of high school. Stuck a 96 ducati 900ss front end on a yamaha xs650. Swapped over the brake discs and everything to the stock yamaha spoked wheel...

That count 754??

I know I'm young and all......

Joel · « **Reply #145 on:** January 08, 2009, 12:40:54 AM »

Quote from: Industrial Cafe on January 07, 2009, 02:15:59 PM

I like kittens.

Puppies are better.

scunny · « **Reply #146 on:** January 08, 2009, 02:34:47 AM »

well said havoc

eldar · « **Reply #147 on:** January 08, 2009, 06:23:10 AM »

I guess there ARE other bikes that use 21s huh. And they are heavier than the cb. Well I would call that obstacle overcome. I like the rims on the vtx, if they weren't so pricey, I would say to fit them on.

Geeto67 · « **Reply #148 on:** January 08, 2009, 06:35:25 AM »

to be clear, nobody here is saying the 21" rim isn't strong enough, were he to use a 80-90mm tire that would not support the weight of a 500lb cb. He found a 3.00 inch rim and a tire that would support it so there is no issue there. Once again people are opening thier mouths without reading.

Eldar, if I am a jerk, and PJ is a jerk then without a doubt you are one as well, you have contributed every inch to being an outright cockbag as the next person in this thread so stop pretending you are on some moral high horse. You are every inch the tool tou claim us to be.

crazypj · « **Reply #149 on:** January 08, 2009, 06:56:37 AM »

I've removed my inflammatory posts, had my fun, just don't get personal E, seems like you are defending your opinion.
I've seen some or your 'help', didn't challenge most of it unless there was a chance someone would get hurt/killed
Also, if you actually read through, I think I'm the only person who supplied any meaningful information. (link to spoke calculator and reason for not cutting threads on spokes)
Just about everything else is opinion and/or anecdotal
Just because I think its going to look bad doesn't mean it shouldn't be safe as possible.
21" or 23" wheels may be slightly more flexible but they will have no problems supporting weight, not sure who said they would be weak?
BTW,
there is a saying 'in the trade' ( and probably other retail outlets?)

"I've never met a customer I didn't like, some when they enter the shop, some when they leave"

PJ

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Author Topic: 21 inch cafe? (Read 62134 times)

eldar

eldar

billybobobrain

eldar